Results
Your result is classfied as
| FFMI | |
| Normalized FFMI | |
| Fat-free mass | |
| Total body fat |
FFMI Calculator - Fat-Free Mass Index Calculator for Body Composition
The FFMI Calculator helps you measure your Fat-Free Mass Index — a value that indicates your level of muscularity relative to height. Unlike BMI, FFMI separates fat from muscle and is widely used in bodybuilding, fitness training, and physique evaluation.
How to Use the FFMI Calculator
Enter the following details:
- Height (cm or ft/in)
- Weight (kg or lbs)
- Body Fat Percentage (%)
The calculator uses this data to estimate your lean body mass and then compute FFMI.
FFMI Formula
1. Lean Body Mass = Weight × (1 − Body Fat %)
2. FFMI = Lean Body Mass (kg) ÷ (Height in m)²
3. Normalized FFMI (optional):
FFMI + 6 × (1.8 − Height in meters) (adjusted for height differences)
Example
Weight: 80 kg
Body Fat: 15% → Lean Mass = 68 kg
Height: 1.75 m
FFMI = 68 / (1.75 × 1.75) = 22.2
FFMI Classification
- < 17: Below average
- 17 – 19: Average
- 19 – 21: Athletic
- 21 – 23: Excellent
- 23 – 25: Advanced
- 25+: Highly muscular / enhanced
Common Use Cases
- Tracking lean muscle progress
- Bodybuilding and physique judging
- Fitness and fat loss evaluations
- Monitoring natural vs enhanced muscularity
Why Use an FFMI Calculator?
FFMI is a better alternative to BMI for athletic individuals. It highlights true muscle mass and helps determine natural physique limits, making it valuable for serious lifters and coaches.
Frequently Asked Questions (FAQs)
How is FFMI different from BMI?
FFMI excludes fat mass, making it ideal for athletes. BMI does not separate muscle and fat.
What is a good FFMI score?
20–23 is excellent. Over 25 may indicate performance-enhancing substances unless genetically gifted.
Can women use this calculator?
Yes, but the scale is mostly designed for male athletes. Women’s FFMI will naturally be lower.
Do I need body fat % to use it?
Yes, a reliable estimate or measurement is needed to calculate lean body mass accurately.
How accurate is FFMI?
It provides a reliable muscularity indicator, but accuracy depends on correct body fat input.
Related tools: BMI Calculator, Fat Calculator, BMR Calculator.